Psychological distress confirmed as predictor of long-term back-related functional limitations in primary care settings.

Background and Objective: Among the possible predictors of back pain outcomes that have been studied, indices of psychological distress have been found to have a high prognostic value. This study aimed at assessing the validity of a predictive model of long-term back-related functional limitations that is based on psychological distress, in a new sample of subjects.
Study Design and Setting: The study was conducted with 860 French-speaking workers who consulted for nonspecific back pain in primary care settings of the Quebec City area. They were interviewed at baseline and again 2 years later. Psychological distress and back-related functional limitations were measured respectively with items drawn from the Symptom Checklist 90 Revised and the Roland-Morris Disability Questionnaire. Analyses were conducted by forcing the model previously developed on a sample of English-speaking health maintenance organization (HMO) members of Washington state.
Results: The model correctly classified 82% of subjects as to their functional limitation status at 2 years. The accuracy of the prediction was similar to that reported in the original study.
Conclusion: The fact that this predictive model of back-related functional limitations led to similar results in a different sample of subjects and in another language brings strong support to its validity.